Week 3 Lectures

Question 1

natural selection acts on phenotype, but evolution results from changes in allele frequency

Answer 1

changes in allele frequency must affect development. natural selection is not forward looking, it is simply the result of differences in survival and reproduction among variants that exist at any time in a population

Question 2

CORN

Answer 2

after a certain time point, the genetic variation is exhausted, and cannot evolve beyond that limit

Question 3

tradeoffs influence the course of evolution

Answer 3

tradeoffs: females prefer to mate with longer lower fins. it doesn’t keep on getting longer, because they stop getting streamlined/fast swimming

Question 4

natural selection can lead to complexity

Answer 4

optic nerve cells/pigmented cells->eyes =very very complex. squid eye does not have a blind spot

Question 5

phylogeny and systematics

Answer 5

evolution is about natural selection/genetic drift/speciation, and the pattern of life’s history. major goal is to reconstruct the history of life on earth as to learn about the resistance of organisms/ how they evolved, help us to understand their biochemical processes

Question 6

darwin’s letter to thomas huxley 1857.

Answer 6

darwin spoke of genealogical trees. haeckel also drew a pedigree of man 1874 (iconography) because we are the most complex being/religion and science are so intertwined

Question 7

richard owen and homology

Answer 7

anatomical homology: same bones used for different things; had the same common ancestor

Question 8

phylogenetics: birds

Answer 8

birds have nespid characteristics that from dinosaurs

Question 9

types of phylogenetic trees

Answer 9

monophyletic, paraphyletic, polyphyletic

Question 10

synapomorphy

Answer 10

shared derived trait; used for identifying monophyletic clades

Question 11

symplesiomorphy

Answer 11

shared primitive trait, a trait that is shared by a group but evolved prior to the common ancestor of the group